public class 圆 {
    public static void main(String[]args){yuanmianji(5);
    }public static void yuanzhouchang(double r){
        double pi=3.14;
        System.out.println("圆的周长为："+2*r*pi);
    }public static void yuanmianji(double r) {
        double pi=3.14;
        System.out.println("圆的面积为:"+pi*r*r);
    }
}
